This invention relates to a gear cutting method and a gear cutting apparatus for generating a bevel gear using a spiral bevel gear cutter having mounted thereon a blade material made of a high-speed tool steel.
When generating a bevel gear such as a spiral bevel gear or a hypoid gear using a spiral bevel gear cutter, a spiral gear cutting machine is used. An outline of a spiral bevel gear cutting machine will be described with reference to FIG. 21. FIG. 21 illustrates a brief construction of a spiral bevel gear cutting machine.
In a spiral bevel gear cutting machine 1, an annular milling cutter 2 as a spiral bevel gear cutter is mounted on a main shaft 4 of a cutter head 3, and a work 5 is attached to a work shaft 6 side. Rotational center axes of the main shaft 4 and the work shaft 6 are disposed to be crossing when viewed on a plane. The cutter head 3 is supported to be revolvable round the mechanical center axis, and the main shaft 4 is rotatably supported on the cutter head 3. The work shaft 6 rotates in cooperation with rotation of the main shaft 4 and revolution of the cutter head 3. In FIG. 21, numeral 7 indicates a nozzle for supplying a cutting oil 8.
The annular milling cutter 2, as shown in FIG. 22, comprises a plurality of blade materials 10 made of a high-speed steel mounted in a ring form on the outer periphery of a disk-formed main body 9.
When generating teeth on the work 5 using the spiral bevel gear cutting machine 1, the work 5 is mounted to the work shaft 6 side, and the annular milling cutter 2 is mounted to the main shaft 4 side. The cutter head 3 is revolved and the main shaft 4 is driven rotatively to revolve and rotate the annular milling cutter 2, and the work shaft 6 is rotated to rotate the work 5. The annular milling cutter 2 revolves round the mechanical center while rotating together with a virtual crown gear so that a tooth surface of the virtual crown gear is depicted by a cutting edge of the annular milling cutter 2. The work 5 is rotated to mesh with the tooth surface so that the tooth surface is generated on the work 5. During the gear cutting work, the cutting oil 8 is fed from the nozzle 7 to the cutting portion to lubricate and cool the cutting portion.
In order to reduce the machining cost in teeth generation by the annular milling cutter 2, it is necessary to rotate the annular milling cutter 2 at a higher speed so that the machining be carried out in a short time. In the present situation, however, the peripheral speed (cutting speed) of the annular milling cutter 2 is limited due to the wear of the cutter, and thus there has been a limitation in reduction of the machining time. This is presently an obstacle to the reduction of the machining cost.
Recently, a high-speed machining technique using an annular milling cutter 2 applied with the blade material 10 made of a cemented carbide has been developed, and thus generation of teeth by the spiral bevel gear cutting machine 1 has become more efficient. In the case of using the annular milling cutter 2 applied with the blade material made of cemented carbide, a heat crack will develop if machining is performed under the supply of cutting oil, because cemented carbide is fragile. For this reason, in the case of using the annular milling cutter 2 applied with the blade material 10 made of cemented carbide, use of a dry cutting method becomes a mainstream in which machining is performed without the supply of cutting oil. Since cemented carbide is much higher in both heat resistance and wear resistance than the high-speed steel, no problem occurs even if such a dry cutting is performed.
As mentioned above, the machining efficiency is improved by using the annular milling cutter 2 applied with the blade material 10 made of cemented carbide and it may become possible to reduce the machining cost by the improved machining efficiency. However, the blade material 10 made of cemented carbide is so expensive that the total cost becomes extremely high even if the machining efficiency is improved. In addition, since cemented carbide is fragile, there is a fear that a sudden crack may occur. For this reason, the blade material 10 made of cemented carbide is not presently in wide practical use.
The present invention has been accomplished in view of the above-mentioned circumstances and it is an object of the present invention to provide a gear cutting method and a gear cutting apparatus capable of considerably improving the cutting speed without using a blade material made of cemented carbide for the spiral bevel gear cutter. Another object of the present invention is to provide a spiral bevel gear cutter capable of greatly improving the cutting speed without using a blade material of cemented carbide.
In accordance with the present invention which attains the above objects, there is provided a gear cutting method for a bevel gear using a spiral bevel gear cutter having a blade material made of a high-speed tool steel mounted on a cutter main body and coated with at least one layer of a film of a composition substantially comprising TiAlN, by which teeth are generated by dry cutting without using a cutting oil at a cutting speed in a range from 20 to 400 m/min.
According to the present gear cutting method, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like.
Further, the gear cutting method according to the present invention which attains the above objects generates teeth of a bevel gear using a spiral bevel gear cutter having a blade material made of a high-speed tool steel mounted on a cutter main body, the blade material being coated with at least one layer of a film of a composition substantially comprising:
(Ti(1xe2x88x92x)Alx)(NyC(1xe2x88x92y))
Where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the present method, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like.
Still further, the gear cutting method which attains the above objects is characterized in that teeth of a bevel gear are generated using a spiral bevel gear cutter having a blade material made of a high-speed tool steel mounted on a cutter main body, the blade material being coated with at least one layer of a film of a composition substantially comprising:
(Ti(1xe2x88x92x)Alx)(1xe2x88x92w)(NyC(1xe2x88x92y))w
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x88x92yxe2x89xa61.0
0.45xe2x89xa6wxe2x89xa60.55,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the present method, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like, and N and C be contained in amounts equal to or larger than Ti and Al which are metal elements, thereby solid solution reinforcement of the coating film being expectable.
Yet further, according to the present invention which attains the above objects, there is provided a gear cutting method characterized in that teeth of a bevel gear are generated using a spiral bevel gear cutter having a blade material made of a high-speed tool steel mounted on a cutter main body, where a nitride forming element is represented by M, the blade material being coated with at least one layer of a film of a composition substantially comprising:
(TizAlxM(1xe2x88x92zxe2x88x92x))(1xe2x88x92w)(NyC(1xe2x88x92y))w
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0
0.15xe2x89xa6zxe2x89xa60.8
0.7xe2x89xa6(z+x) less than 1.0
0.45xe2x89xa6wxe2x89xa60.55.
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the present method, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like, and N and C be contained in amounts equal to or larger than Ti and Al which are metal elements, thereby solid solution reinforcement of the coating film being expectable.
Yet further, the gear cutting method of the present invention is characterized in that the cutting speed is in a range from 40 to 120 m/min.
Yet further, the gear cutting method according to the present invention is characterized in that teeth are generated while blowing air against the cutting portion to remove cutting debris. Yet further, during the gear cutting work, teeth are generated while blowing air against the cutting portion in a direction along the rotational direction of the spiral bevel gear cutter to blow off cutting debris, and from the outer periphery towards the center of the spiral bevel gear cutter to blow off cutting debris from a space between the blade materials, and cooling air is blown against the work. This prevents cutting debris from biting into the work.
Yet further, the generated gear is a bevel gear used for an automotive reduction apparatus.
A gear cutting apparatus of the present invention which attains the above objects for generating a bevel gear is characterized in that a tool main shaft of a cutter head supporting a spiral bevel gear cutter and a work shaft supporting a work are disposed so that rotational center axes thereof intersect with each other, the cutter head is supported to be revolvable round a mechanical center, the spiral bevel gear cutter and the work are meshed with each other by rotating the work shaft in cooperation with rotation of the tool main shaft and revolution of the cutter head, in which the spiral bevel gear cutter has a blade material mounted thereon and coated with at least one layer of a film of a composition substantially comprising TiAlN, teeth are generated by dry cutting without using a cutting oil at a cutting speed in a range from 20 to 400 m/min.
With the present apparatus, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like.
Still further, according to the present invention which attains the above objects, there is provided a gear cutting apparatus for generating a bevel gear characterized in that a tool main shaft of a cutter head supporting a spiral bevel gear cutter and a work shaft supporting a work are disposed so that rotational center axes thereof intersect with each other, the cutter head is supported to be revolvable round a mechanical center, the spiral bevel gear cutter and the work are meshed with each other by rotating the work shaft in cooperation with rotation of the tool main shaft and revolution of the cutter head, in which the spiral bevel gear cutter has a blade material mounted thereon and coated with at least one layer of a film of a composition substantially comprising:
(Ti(1xe2x88x92x)Alx)(NyC(1xe2x88x92y))
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the present apparatus, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like.
Yet further, according to the present invention which attains the above objects, there is provided a gear cutting apparatus for generating a bevel gear characterized in that a tool main shaft of a cutter head supporting a spiral bevel gear cutter and a work shaft supporting a work are disposed so that rotational center axes thereof intersect with each other, the cutter head is supported to be revolvable round a mechanical center, the spiral bevel gear cutter and the work are meshed with each other by rotating the work shaft in cooperation with rotation of the tool main shaft and revolution of the cutter head, in which the spiral bevel gear cutter has a blade material mounted thereon and coated with at least one layer of a film of a composition substantially comprising:
(Ti(1xe2x88x92x)Alx)(1xe2x88x92w)(NyC(1xe2x88x92y))w
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0
0.45xe2x89xa6wxe2x89xa60.55,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the apparatus according to the present invention, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like, and N and C be contained in amounts equal to or larger than Ti and Al which are metal elements, thereby solid solution reinforcement of the coating film being expectable.
Yet further, according to the present invention which attains the above objects, there is provided a gear cutting apparatus for generating a bevel gear characterized in that a tool main shaft of a cutter head supporting a spiral bevel gear cutter and a work shaft supporting a work are disposed so that rotational center axes thereof intersect with each other, the cutter head is supported to be revolvable round a mechanical center, the spiral bevel gear cutter and the work are meshed with each other by rotating the work shaft in cooperation with rotation of the tool main shaft and revolution of the cutter head, in which the spiral bevel gear cutter has a blade material mounted thereon, where a nitride forming element is represented by M, and coated with at least one layer of a film of a composition substantially comprising:
(TizAlxM(1xe2x88x92zxe2x88x92x))(1xe2x88x92w)(NyC(1xe2x88x92y))w
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0
0.15xe2x89xa6zxe2x89xa60.8
0.7xe2x89xa6(z+x)xe2x89xa61.0
0.45xe2x89xa6wxe2x89xa60.55;
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the apparatus according to the present invention, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like, and N and C be contained in amounts equal to or larger than Ti and Al which are metal elements, thereby solid solution reinforcement of the coating film being expectable.
Yet further, the gear cutting apparatus of the present invention is characterized in that the cutting speed is in a range from 40 to 120 m/min.
Yet further, the gear cutting apparatus of the present invention is characterized by air supply means provided for blowing air to blow off cutting debris against the cutting portion. Yet further, a first air nozzle is provided for blowing air to blow off cutting debris against the cutting portion in a direction along the rotational direction of the spiral bevel cutter, and a second air nozzle is provided for blowing air to blow off cutting debris from a space between the blade materials, and cooling air is blown against the work. and a third air nozzle is provided for blowing work cooling air.
This prevents cutting debris from biting into the work.
A spiral bevel gear cutter according to the present invention which attains the above objects is characterized by a blade made of a high-speed tool steel mounted on a cutter main body and coated with at least one layer of a film of a composition substantially comprising TiAlN, teeth are generated by dry cutting without using a cutting oil at a cutting speed in a range from 20 to 400 m/min.
With the present invention, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like.
Further, a spiral bevel gear cutter which attains the above objects is characterized by a blade made of a high-speed tool steel mounted on a cutter main body and coated with at least one layer of a film of a composition substantially comprising:
(Ti(1xe2x88x92x)Alx)(NyC(1xe2x88x92y))
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the present invention, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like.
Still further, a spiral bevel gear cutter which attains the above objects is characterized by a blade made of a high-speed tool steel mounted on a cutter main body and coated with at least one layer of a film of a composition substantially comprising:
(Ti(1xe2x88x92x)Alx)(1xe2x88x92w)(NyC(1xe2x88x92y))w
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0
0.45xe2x89xa6wxe2x89xa60.55,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
With the present invention, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like, and N and C be contained in amounts equal to or larger than Ti and Al which are metal elements, thereby solid solution reinforcement of the coating film being expectable.
Yet further, a spiral bevel gear cutter which attains the above objects is characterized by a blade made of a high-speed tool steel mounted on a cutter main body, where a nitride forming element is represented by M, and coated with at least one layer of a film of a composition substantially comprising:
(TizAlxM(1xe2x88x92zxe2x88x92x))(1xe2x88x92w)(NyC(1xe2x88x92y))w
where, 0.2xe2x89xa6xxe2x89xa60.85,
0.2xe2x89xa6yxe2x89xa61.0
0.15xe2x89xa6zxe2x89xa60.8
0.7xe2x89xa6(z+x)xe2x89xa61.0
0.45xe2x89xa6wxe2x89xa60.55,
the cutting speed being in a range from 20 to 400 m/min, and teeth are generated by dry cutting without using a cutting oil.
According to the present invention, teeth of a bevel gear can be generated at a greatly improved cutting speed without using any expensive blade material such as a tool made of cemented carbide or the like, and N and C be contained in amounts equal to or larger than Ti and Al which are metal elements, thereby solid solution reinforcement of the coating film being expectable.
The cutting speed is in a range from 40 to 120 m/min.
Yet further, teeth are generated while blowing air to blow off cutting debris against the cutting portion. Yet further, during the gear cutting work, teeth are generated while blowing air against the cutting portion in a direction along the rotational direction of the spiral bevel gear cutter to blow off cutting debris, and from the outer periphery towards the center of the spiral bevel gear cutter to blow off cutting debris from a space between the blade materials, and cooling air is blown against the work.
This prevents cutting debris from biting into the work.
Yet further, the generated gear is a bevel gear used for an automotive reduction apparatus.